The subject invention is directed toward the valve art and, more particularly, to an improved rising stem plug valve.
The invention is particularly suited for manufacture as a molded, all plastic or suitable resin (e.g., perfluoroalkylvinylether or tetrafluoroethylene) valve and will be described with reference thereto; however, it should be understood that the invention can be embodied in many specific forms and manufactured from a variety of materials.
Valves used in systems handling highly corrosive acidic or caustic solutions are frequently formed entirely from molded plastics or similar resinous materials such as tetrafluoroethylene. There has been an ongoing attempt to simplify the design and manufacture of such valves. Typically, the focus has been on reducing the number of components. For example, by combining what were previously separate parts into single piece moldings there has resulted substantial savings in manufacture and assembly. However, in some instances, the component combining has not produced the most efficient or effective valve from an operating or functioning standpoint.